Server Overload

Saturday 24 April 2004 9:01:11 pm

Hi I am having a problem with servier overload while using Exponential. This has been an ongoing problem that I thought had been solved. I am currently building a large site on the same server that is hosting our current live site. This is what my ISP has to say about the problem:

This is a 1 1/4 gig RAM machine, with a 1 gig swap space, and
something saturates every bit of that space almost instantly. It
happened twice this afternoon. Can you correlate anything you did
with the overloads?

During the peaks, the system load, measured as the average number of
processes ready to run over the most recent minute, was over 80.
That is beyond saturated. I could not even log in remotely for some
time, until it had partially worked off whatever induced the load.

The problem seems to happen mainly when I am adding content to the web site.

The site is linux
Apache/1.3.29 Ben-SSL/1.52 (Unix) FrontPage/5.0.2.2634 AuthMySQL/2.20 PHP/4.3.6 mod_jk/1.1.0
PHP 4.3.6

These are teh Apache loaded modules:
Loaded Modules mod_scoreboard_send, mod_frontpage, mod_security, mod_auth_mysql, mod_bandwidth, mod_php4, mod_jk, apache_ssl, mod_setenvif, mod_so, mod_usertrack, mod_headers, mod_expires, mod_digest, mod_auth, mod_access, mod_rewrite, mod_alias, mod_userdir, mod_speling, mod_actions, mod_imap, mod_asis, mod_cgi, mod_dir, mod_autoindex, mod_include, mod_status, mod_negotiation, mod_mime, mod_log_config, mod_env, http_core

Part of my problem is when I run the site on my machine it does not have this problem. It runs just fine. But when I run it on my hosting companies serfver we get a server overload. Now my machine is significantly different - Windows XP instead of Linux, the database is on my computer instead of remote, etc. Any ideas??

Monday 26 April 2004 6:57:43 am

Try this:
- Enable memory_limit in PHP
Exponential needs more than 8Mb (which is default), but should do fine with about 20Mb. Enabling memory_limit will stop php processess that starts "run away"
- Decrease MaxClients in httpd.conf. You run out of memory. It is better to queue incomming requests than to start swapping.
- Try a PHP accelerator. Apache's memory footprint will increase because of this, but Exponential will be less CPU intesive so you will be able to server more requests.